Tofacitinib chemically is 3-{(3R,4R)-4-methyl-3-[methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino]piperidin-1-yl}-3-oxopropanenitrile of Formula I.

Tofacitinib is a Janus kinase 3 (JAK3) inhibitor.
U.S. Pat. No. RE41,783 provides a process for the preparation of a tofacitinib intermediate, (1-benzyl-4-methylpiperidin-3-yl)-methylamine, wherein 1-benzyl-4-methylpiperidin-3-one is stirred with methylamine in the presence of acetic acid for 16 hours at room temperature, then the mixture obtained is further stirred with triacetoxy sodium borohydride for 24 hours to provide (1-benzyl-4-methylpiperidin-3-yl)-methylamine. The amination process described in U.S. Pat. No. RE41,783 is a two-step process, wherein an imine intermediate is first formed in situ by the reaction between 1-benzyl-4-methylpiperidin-3-one and methylamine. This imine intermediate on treatment with triacetoxy sodium borohydride provides (1-benzyl-4-methylpiperidin-3-yl)-methylamine. This process involves long reaction hours and costly reagents, for example, triacetoxy sodium borohydride.
U.S. Pat. No. 6,696,567 provides a process involving six steps for the preparation of (1-benzyl-4-methylpiperidin-3-yl)-methylamine starting from 4-methylpyridine and benzylchloride. The process provided therein involves the use of costly and corrosive reagents, for example, borontrifluoride etherate, hydrogen peroxide, and triacetoxy sodium borohydride.
U.S. Pat. No. 7,084,277 provides a process involving four steps for the preparation of (1-benzyl-4-methylpiperidin-3-yl)-methylamine starting from 4-methyl-pyridin-3-ylamine. The process provided therein involves the use of costly starting material and/or reagents, for example, 4-methyl-pyridin-3-ylamine, rhodium on alumina and sodium triacetoxyborohydride.
The prior art processes for the preparation of (1-benzyl-4-methylpiperidin-3-yl)-methylamine involve a number of reaction steps and make use of costly and corrosive starting materials and/or reagents. Accordingly, these processes are not suitable at an industrial scale. Therefore, there is still a need in the art to develop an economically attractive process for the preparation of (1-benzyl-4-methylpiperidin-3-yl)-methylamine.